Nucleases are enzymes that degrade nucleic acids (e.g., deoxyribonucleic acids, DNA, and ribonucleic acids, RNA) and exist in various biological materials. These enzymes are involved in DNA and RNA metabolism, including degradation, synthesis and genetic recombination of nucleic acids. Nucleases are generally classified into exonucleases and endonucleases according to their mode of action. The former type acts on the terminus of a nucleic acid molecule and hydrolyzes the chain progressively to liberate nucleotides, while the latter type cleaves a phosphodiester bond in a nucleic acid molecule distributively to produce DNA or RNA fragments or oligonucleotides.
Deoxyribonucleases (DNases) are phosphodiesterases capable of hydrolyzing polydeoxyribonucleic acid. DNases have been purified from various species to various degrees. Among other uses, DNases find use as reagents in a variety of protocols in molecular biology. DNases have also been used for therapeutic purposes, for example, to reduce the viscosity of pulmonary secretions in such diseases as pneumonia and cystic fibrosis, thereby aiding in the clearing of respiratory airways.
Literature
Makarova et al. (2002) Nucleic Acids Res 30:482-496; Makarova et al. (2006) Biology Direct 1:1-26; Wiedenheft et al. (2009) Structure 17:904.